The invention relates to the diagnosis of balance disorders, and particularly to a network-based system for remotely evaluating balance-related diagnostic test data.
The brain maintains a sense of spatial orientation and equilibrium by integrating and interpreting a variety of different sensory inputs from the visual, vestibular (inner ear), and somatosensory (muscles, skin, and joints) systems. The most complex source of spatial cues is the vestibular system of the inner ear. Indeed, studies have shown that the vast majority of patients complaining of dizziness have a vestibular abnormality.
The inner ear has two types of spatial orientation sensors. Three endolymphatic-fluid-filled semi-circular canals provide sensory information about velocity, rotation, and angular motion. Two otolith organs in each inner ear, the utricle and the saccule, sense horizontal and vertical acceleration, respectively. Specialized hair cells in the otoliths and the ampullae (the dilated portions of the semi-circular canals) are displaced by movement in one direction or the other. These displacements are converted in neural signals, which are transmitted by the vestibular nerve to the brain. When the head is in a normal upright position, the hair cells in each ear fire equally at a static rate. When the head tilts to the right or to the left, the hair cells in each ear fire at different rates. The central nervous system recognizes the difference in the firing rate to determine where the head is in space.
The sensory data from the inner ear is complemented by visual cues from the eyes and somatosensory spatial cues from the muscles and skin, which sense pressure and muscle tensioning caused by standing, sitting, or lying down.
Sensory mismatch occurs when the various sensory inputs of the body do not agree with one another. For example, a room on a ship in a stormy sea may look upright at the same time the gravity sensors in the inner ear and pressure sensors in the feet indicate that the room is tilted at an angle. Sensory mismatch can result in nausea, queaziness, and disorientation.
Several different conditions can cause the balance system to malfunction. Labyrinthitis and Vestibular Neuronitis are conditions that describe the inflammation of the inner ear or the vestibular nerve, typically caused by a viral infection. These conditions are characterized by a sudden onset of vertigo which is xe2x80x9cspinningxe2x80x9d in nature, extreme nausea, and vomiting.
Endolymphatic Hydrops is a condition of the inner ear related to the inability of the ear to regulate its fluid balance, resulting in an episodic buildup of pressure within the balance and hearing organs. This disorder is characterized by spontaneous episodes of vertigo lasting up to several hours, fullness of the ear, xe2x80x9cringingxe2x80x9d or noise in the ear, and/or hearing loss. When all of these symptoms are present, the disorder is described as Meniere""s Disease. Endolymphatic Hydrops has many causes, including Labyrinthitis, perilymphatic fistula, concussions, noise trauma, autoimmune inner ear disease, and ear surgery. This disorder is thought to be related to herpetic group viruses. Immune stimulation from allergies, stress, illness or hormonal changes tend to worsen these symptoms.
Benign Paroxysmal Positional Spinning (BPPV) is a condition characterized by the positional onset of vertigo. Brief episodes of vertigo may be caused by lying down, rolling over in bed, or tilting the head back to look up. Canalithiasis, a form of BPPV associated with vertigo lasting only a few seconds, is thought to be caused by misplaced calcium carbonate crystals (otoconia) that have been dislodged from the inner ear and which float freely within the semi-circular canals in response to gravity. Cupulolithiasis, a form of BPPV associated with vertigo lasting several minutes, is caused by misplaced otoconia stuck to the cupula that constantly stimulate the balance sensor.
Perilymphatic fistula is caused by a hole in the inner ear that leaks endolymphatic fluid into the middle ear. Leakage results in brief episodes of vertigo triggered by rapid changes in middle ear pressure, such as that caused by coughing, sneezing, lifting, scuba diving, head trauma, or rapid changes in altitude.
Vertebribasular Insufficiency (VBI) is a common vascular disorder characterized by decreased blood flow through the vertebrobasilar artery system, which can result in an abrupt onset of vertigo that resolves after several minutes of lying down. Such episodes are accompanied by other VBI symptoms, including visual hallucinations, drop attacks, visual field deficits, diplopia, and headache.
Otoxicity is a condition characterized by damage done to the hearing and balance systems by drugs. Common medications that can permanently damage the inner ear system include Aminoglycoside antibiotics and Cisplatin. Symptoms may include gait unsteadiness, imbalance, and oscillopsia (a bouncing sensation of the horizon).
Other disorders are characterized by gravity sensors in the otolith organs being excessively responsive to internal pressure changes such as that caused by physical activity and sound. Damage can also be caused by tumors and viral infections that affect the vestibular nerve.
Vestibular abnormalities cause not only the common symptoms of dizziness, spinning, unsteadiness, and nausea, but also cognitive dysfunction, including short-term memory deficits, inability to concentrate or focus on a task, panic attacks, and depression. These cognitive symptoms are caused by the brain""s natural compensation mechanisms. To suppress the sensory input from the malfunctioning ear, the brain decreases the relative function of the brain""s reticular activating system (the portion of the brain responsible for xe2x80x9cawarenessxe2x80x9d or the feeling of being xe2x80x9cawakexe2x80x9d or xe2x80x9cclearxe2x80x9d) which secondarily increases the activity of the limbic system (the portion of the brain responsible for moods and emotions).
Approximately 12.5 million physician""s office visits per year, or five to ten percent of all office visits, are for the complaint of dizziness. A National Institutes of Health study estimates that forty percent of the population over the age of forty have experienced or will experience a xe2x80x9cdizzinessxe2x80x9d disorder during their lifetime. But dizziness affects the young as well. Each year over 450,000 people, mostly young adults, suffer concussions or mild head injuries. Of those requiring short-term hospitalization, a large majority complain of persistent symptoms of dizziness or memory loss.
Unfortunately, many sufferers of dizziness or vertigo disorders do not receive proper diagnosis or therapy. Because the symptoms are vague, and the possible causes multitudinous, sufferers are often improperly diagnosed. Worse, sufferers are often treated as xe2x80x9cproblem patientsxe2x80x9d or inappropriately referred to psychiatrists and neurologists.
Athletes in contact and high-impact sports experience a high incidence of vestibular abnormalities caused by mild to severe head injuries. Unfortunately, athletes in professional and even college sports are seldom adequately diagnosed for vestibular abnormalities following a jarring collision, blow to the head, or other minor injury before being sent back onto the playing field.
There are a variety of tests for diagnosing balance disorders of the vestibular system. One test is a hearing test. Balance disorders are often accompanied by problems with hearing especially hearing of low frequencies. Another test is a posturography test, in which a person stands on a moving platform and the movement of the ankles and hips are measured. Posturography tests the vestibular-spinal reflex, which is manifested in the movements various body muscles make to maintain postural balance and coordination. Posturography is useful for detecting disorders in the otolith organs of the ear, because both the somasensatory system and the otoliths detect acceleration (including gravity).
The Vestibular Autorotational Test (VAT(copyright)) evaluates the function of the vestibulo-ocular reflex (VOR) by measuring how quickly and accurately our eyes move to compensate for head movement. The VOR allows us to have clear vision during movement. For example, when a person turns his head 30 degrees to the right, the eyes should simultaneously turn 30 degrees to the left. If the eyes turn too little or turn too much, it suggests that the vestibular system may be damaged. The vestibular ocular reflex test is useful in detecting disorders originating in, or affecting, the semi-circular canals of the ear. Sensory input from the semi-circular canals allows the brain to generate eye movements that match the velocity of the head movement.
Despite the existence of various balance dysfunction tests and many methods of treatment, balance disorder treatment is underutilized by the public at large.
Various aspects of the present invention address at least some of the needs of the prior art. In one aspect, the present invention provides a system for diagnosing balance function comprising a test administration center at which a plurality of balance diagnostic tests are administered on a patient, and a remote test evaluation center at which said diagnostic data is evaluated by a skilled clinician, leading to a diagnosis of said patient. A computer network links, and transfers data from, the test administration center to both the test evaluation center, where the data is evaluated, and to a patient database, where the data is stored.
In another aspect, the present invention provides a process for diagnosing the balance system of a patient, the process comprising the steps of a primary care physician of the patient referring the patient to the balance disorder diagnostic provider, the patient registering with the provider and completing a questionnaire for the provider; the provider obtaining authorization from an insurance carrier of the patient to administer the diagnostic balance tests; the patient scheduling an appointment for a plurality of diagnostic balance tests; an affiliate of the provider administering, at the appointed time, the plurality of diagnostic balance tests on the patient using diagnostic testing machines that generate diagnostic data, said plurality of diagnostic balance tests being administered at a first location; a network transmitting the diagnostic data from said diagnostic testing machines to a patient database that stores said diagnostic data; the provider retrieving, at a second location distinct and independent from the first location, the diagnostic data from said patient database; the provider evaluating the diagnostic data to diagnose the patient; the provider recommending therapy to improve the patient""s vestibular functioning; the provider forwarding the diagnosis and recommended therapy to the primary care physician; and the primary care physician referring the patient to the clinic for therapy.
A further aspect of the present invention provides widespread access to state-of-the-art diagnostic modalities. Another aspect of the present invention provides off-site xe2x80x9cexpertxe2x80x9d interpretation of balance dysfunction test data and expert guidance through a global network. Yet another aspect of the present invention provides a platform that integrates a plurality of diagnostic tools, transfers the associated data to a database on the global network, and provides for off-site diagnosis and customization of therapy. Further aspects of the present invention link a regional balance center, a satellite balance testing center, the primary care physician, the patient, and a database through a global computer network. Another aspect of the present invention centrally stores clinical and diagnostic information.
One of the advantages of the present invention is that it gives patients, healthcare providers, athletes, coaches, physical trainers, and others a more complete picture of how well the vestibular system is interacting with the body and brain. Another advantage is that it aids in accurate evaluation and treatment of the specific sensory abnormality by assisting the healthcare provider in distinguishing the source of the symptoms. A further advantage of the present information is that it promotes a team approach to working with patients and athletes, by coordinating athletic trainers with physicians and therapists.
A further advantage of the system and procedure of the present invention is that it provides cost-effective screening, diagnosis, and customized therapeutics for patients with vestibular based disorders. A yet further advantage is that a person seeking treatment can apply and set up an appointment for treatment from any personal computer linked to the global network.
Another advantage of the system and procedure of the present invention is that it facilitates early and aggressive vestibular therapy to minimize and compensate vestibular abnormalities. Administered early after a concussion or mild head injury, aggressive vestibular therapy helps the brain to learn to compensate for vestibular abnormalities without suppressing secondary cerebral functions. Even administered long after an injury, the present invention helps identify the abnormalities and allow customized therapy to restore cognitive abilities to normal performance.
Another advantage of the system and procedure of the present invention is enhancement of athletic performance. Even minor, subtle vestibular abnormalities, which might be tolerable to an ordinary individual performing ordinary tasks, can impair athletic performance and physical coordination, increasing the risk of further injury. Treatments of athletes in accordance with one aspect of the present invention enhances the vestibulo-ocular reflex (VOR), increasing the athlete""s clarity of vision during rapid eye movement.
The benefits of the present invention redound not only to athletes and concussion sufferers, but also to the elderly and the public at large. Every year, one-third to one-half of the population over age 65 experiences falls, many of which lead to orthopedic injuries, including disabling hip fractures. Many of these falls are due to, or contributed by, underlying inner ear disorders. The present invention""s system and procedure for routine and early detection of balance abnormalities significantly reduces the risk of falling for elderly patients.
Moreover, recent clinical experience suggests that some common processing disorders, such as attention deficit disorder, attention deficit hyperactivity disorder, learning disorder, central auditory processing disorder, and visual processing disorder, may merely be symptoms of an underlying inner ear abnormality. Therapeutic regimens administered in accordance with the present invention will improve, if not completely reverse, such central processing disorders.
Other aspects and advantages of the present invention will be more clearly understood after reference to the following detailed description read in conjunction with the drawings.